NUMERICAL SIMULATION OF TSUNAMIS IN THE VANUATU-FIJI-TONGA REGION FOR A TSUNAMI WARNING SYSTEM IN FIJI
Supervisor: Yuichiro TANIOKA
Two historical earthquakes were selected from the subduction zones of Vanuatu and Tonga for this tsunami simulation studies. The earthquake magnitude for the Vanuatu trench simulated tsunami was Mw7.7 and that of the Tonga trench tsunami was Mw7.5. Historically tsunamis by these earthquakes were not detected around the Fiji islands so we set the parameters of their fault models which are almost similar to the original fault model, in order to produce ocean floor deformations capable of generating the hypothetical tsunamis through numerical simulation. The tsunami simulation code used in this study, TSNAMI4s was written and developed by Tanioka.
Travel time charts from the tsunami sources in the Tonga and Vanuatu subduction zones to the shores of the Fiji islands were drawn from the numerical simulation results. Tsunami wave heights at 26 coastal areas of the Fiji islands were computed and compared in order to determine the effect of directivity or the influence of the near-shore seafloor topography. The computed maximum tsunami wave height at Momi Bay and Nabukelevu-i-ra from the simulated Vanuatu trench tsunami is 45 cm and 42 cm respectively
|Citation: ||Bulletin of IISEE, 42, 1-6.|